The following U.S. patents are incorporated by reference herein and disclose representative Aerial and Die Mount Cams:
U.S. Pat. No. 5,487,296 PA1 U.S. Pat. No. 5,101,705 PA1 U.S. Pat. No. 5,231,907
In these references, as the ram of the press is lowered, camming surfaces react between relatively slidable parts to cause a tool to be shifted laterally against a workpiece to effect some stamping, bending, punching or like operations thereon. Such slidable parts are subject to wear at their relatively sliding surfaces. As the accuracy or precision of the press is dependent on repeatability in the movement of its parts, it is extremely important that the wearing surfaces between the sliding parts not be allowed to degrade, and this has led to the necessity of frequently replacing worn surfaces.
Heretofore, it has been common practice to provide wear plates of relatively soft metal on one of the sliding parts. Such plates bear against cast iron surfaces of the opposing part, so that such plates rather than the opposing cast iron part wear away. While this has proven to be helpful, it still has required periodic replacement which may result in downtime for the press during production runs, which becomes a very costly procedure.
In addition, certain prior art, particularly U.S. Pat. No. 5,101,705, discloses a guide arrangement between the slide cam base 13 (sometimes referred to as a cam adapter) and the tool holder or slide cam 17 which prevents meandering of the slide cam 17 (and in turn the tool 43 carried thereby) in the event of wear between the opposed sliding surfaces of the cam adapter and the slide cam. While such design may prevent wandering or meandering of the slide cam, it limits the effective loading that can be imposed between the relatively sliding parts, not merely because of the limited surface area between the parts across which the loading is to be spread, but also because of the design, the working loads impose substantial tensile stresses on the slide cam which are directed laterally as viewed in FIG. 2 of such patent. These stresses are in a direction which tends to fracture the slide cam along a vertical plane coincident with the crest line 15, and thus the design substantially limits the effective working loads the slide cam can safely handle.